WOW! That is good!
I had this last night on two eye of the round roasts from a 1.5 year old buck and one from a yearling doe.
-used plenty of pepper and montreal steak seasoning, also used some italian seasnoning
-I added ~1/2 cup water to make the meat a bit more moist (not sure if it was needed or not)
-no mushrooms, they do not agree with me
-cooked for 4.5 hours on high in a crockpot, the meat was incredibly tender
-used hoagie rolls and pepper jack cheese